Specifically, this thread should cover E39's built after September 2000, namely the post-facelift 2001-2003 model year with either the Hella HID (aka xenon gas-discharge low beam with self-leveling motor) or Hella conventional (aka halogen headlights with the H7 base, 9005 holder, 9006 connector, no ballast, no self-leveling motor).
Note: The cost for a complete set of adjusters for E39's older than September 2000 is only $15 at EAC (compared to $160 for newer adjusters); so the older adjusters are not expected to be the topic of this discussion.

I realize most of this information is known, but it's scattered about (as I found a dozen confusing options just by googling) ... and some of the information was unknown until now (e.g., the materials used); so the main intent of this thread is to consolidate the known & newly recommended options in some sort of ordered usable decision-making list.

As usual, I'll stick my neck out to show my ignorance (headlights are soooo confusing to me but I learn a lot about any problem I run into so this is my starting point)!

As a first stab, here are what I think are the main options available to us for a complete set: 1. New Hella headlights:- OEM (~$710/pair for Halogens, left 63 12 6 900 199/right 63 12 6 900 200, from EAC, ~$1,520/pair Xenons from ECS, PN left 63 12 6 912 433/right 63 12 6 912 434) or
- New Hella headlights, OEM (~?/pair for Halogens, ~$900/pair Xenons from Umnitza).
Note: I do not know if you end up with the same brittle PBT plastic headlight adjusters; if so, this would devalue this choice.

4. Modified-new DJ Auto "FXR" upgraded headlights
(~$?/pair for Halogens, ~$500/pair of "DJAuto Projector 39 Hella Type" Xenons, and ~$700/pair for "DJAuto Projector39 FXR-modified Hella Type" Xenons from Matt at UmNitza.
Note: I do not know if you end up with the same brittle PBT plastic headlight adjusters; if so, this would devalue this choice.

5. Salvage yard headlights
(~$250/pair)
Note: You can sell your old headlights on Craigslist for about ??? to partially recoup your losses.
Note: You'll probably end up with the same brittle plastic PBT headlight adjusters; if so, this would devalue this choice.

7. Buy the "20% glass-filled Delrin" thermoplastic or "Nylon-6" polyamide adjusters:
- (~$210 at bmwheadlightrepairs for both headlights, PN ODO-E39-LITE) or
- (~$170 at Bavauto for both headlights, PN E39 HLA AE) or
- (~$170 at Pelican for both headlights, PN ODO-E39-LITE) or
- (~$161.50 at EAC for both headlights, PN 098816001) or
- (~$150 at fcpgroton for both headlights) or
- (~$60 from Hetpe3b, aka bimmer.netne.net on Craigslist for both headlights) or
- (~$58 + $6 shipping from Hetpe3b, aka bimmer.netne.net from their web site)
- (~$63, including $10 shipping from Hetpe3b, on Ebay for both headlights again from bimmer.netne.net).

8. Buy the aluminum adjusters
(~$160 at EAC for both headlights) <=== THIS IS THE MOST-OFTEN RECOMMENDED OPTION HERE
(~$102 on Ebay for both headlights) <=== (£50 GBP for both headlights + £12 GPB for shipping all four to the USA)

10. Fabricate your own adjusters, either molding or fabricating out of Teflon or HDPE or Delrin & a steel screw & cap:
- (~$5 for both headlights, where you open the headlights for access)
- (~$5 both headlights, where you cut a square in the top of the headlights for access)

The fabrication of two headlight adjusters took just about an hour with nothing more than a vise, a saw, and a 5/32" drill bit. It was actually trivial to make, surprisingly to me (and at a total cost of less than $6 sufficient for three or four vehicles). More details in this thread.

11. Use two zip ties per headlight & adjust by clicks (~$5 for both headlights)

12.Shove a spare length of metal under the lens assembly to keep it rigid in place (~$0 for both headlights) Note: This is what I've done, for now, while I research what permanent solution I'll choose. Interestingly, the light aim is better now than it has been in years!

I'm sure this list is incomplete/inaccurate so please help improve it so that we can update it and then others can refer to our collective tribal knowledge.

BTW, here are some of my favorite threads on the headlights and the headlight adjusters: